1. Field of the Invention
The invention relates to a polarized miniature relay with a switching space located inside the body of a coil winding and in which space a rotary armature assembly is disposed to operate at least one spring contact assembly.
2. Prior Art
By arranging the armature assembly and the working air gap of a relay within the relay coil tube, as opposed to disposing the armature outside the body of the coil, the iron cross-section, or iron mass, can be reduced while preserving the same sensitivity for the relay. In addition a magnet and electric contact system which is disposed within the coil tube can be sealed easily. In a known relay of this kind such as that shown in German Auslegeschrift No. 2,318,812 or British Pat. No. 1,456,861 the body of the coil is made of two parts which are connected together in a form-locking or assembly securing manner. The interior switching space is thus sealed by this construction. However, in such prior art constructions, the armature must be mounted in both halves of the coil body. Therefore, the magnet system does not become operational until the part of the body of the coil which forms the cover is placed in position. At that time the switching space is closed, i.e. the contacts are no longer accessible for adjustment. In addition, in this prior type relay the permanent magnets unless a permanently magnetized armature is used, are disposed at the ends of the body of the coil. Thus for reasons of symmetry at least two permanent magnets have to be used, which makes magnetic balancing of the relay more difficult.
Further, British specification No. 1,246,177 (German Auslegeschrift No. 1,639,417) discloses an unpolarized multicontact relay in which the armature and the contacts are housed in the body of the coil which forms a protective tube. The reciprocal alignment of the magnetic parts on the one hand and the contact springs on the other is effected in this type of construction by a contact carrier which extends longitudinally of and roughly in the middle of the coil while simultaneously serving as a carrier for the pole shoes. The contact carrier has apertures through which operating elements attached to the armature engage. As the contact carrier is made of an insulating material, it must have a large cross-section to have the required strength. Consequently it takes up an unreasonably large amount of space inside the coil tube. Otherwise, the said specification makes no suggestion as to the formation of a polarized relay of the kind named at the beginning.